1905] CURRENT LITERATURE "7 
of numerous starch grains. The wing-like leaves of the ovulate spathe aid in 
___ keeping the flower in a horizontal position, and the petals are specially adapted to 
catch the floating staminate flowers. The exposure of the ovulate flowers and 
the loosening of the staminate flowers occur only during low water. During 
- high water the ovulate flowers are vertical; and the heavy pollen grains can scarcely _ 
| , avoid sinking down upon the erected stigmas. The pollination of Enalus, there- 
_. fore, is both at the surface of the water and beneath it. The development of the 
§ embryo is of the ordinary Alisma-type, with a very large basal suspensor cell. 
At maturity the testa is an easily loosened cap around the embryo, the latter 
escaping entire and developing immediately.—J. M. C 
= Locx?s has been investigating the rate of growth of the giant bamboo (Den- 
| _ drocalamus giganteus) in Ceylon. The stems show a gradually increasing rate 
of growth up to 5™; then a nearly constant rate up to 15™; then a slowly dimin- 
“4 
_ ishing rate to the final height of 30" or more. The average daily rate at a height 
+ of r™is ro°™ per day; at 5—15™, 30°"; and at 20-25", 15°". The greatest growth 
as 
- recorded in 24 hours was 46°™. The daily rate of growth is much increased by 
_ rainfall, the effect being greater the greater the height of the stem. The greatest 
change observed in rate of growth in two successive days was 50 per cent. of the 
@ average rate. Growth is almost always more rapid at night; the average hourly 
growth at heights of 3-12™ between 7:00 A.M. and 5:00 P.M. being 6™™, and 
Ve A between 5:00 P.M. and 7:00 A.M. 16™™; the maximum rate being reached soon 
i at after dark. The curve of sess by day follows very closely that of the percent- 
4 a age moisture of the air.—J. M. C 
| i THE SECOND section of Davis’s?4 Studies on the plant cell is entitled, “‘Activi- 
4 ties of the plant cell.’”’ The activities described are (1) vegetative activities, and 
_ (2) cell division. Cell division is treated under the subheads (a) the events of 
- nuclear division and (b) the segmentation of the protoplasm. The account of 
discussed in detail and considerable attention is paid to the centrosome problem. 
3 The view is expressed that all divisions of chromosomes are longitudinal. The 
-_ evidence in favor of regarding the chromosome as a permanent organ of the 
a cell is regarded as not yet sufficient. In dealing with the segmentation of the 
Bi, protoplasm, the author gives a valuable summary of recent work in this field. 
 —CuHartes J. CHAMBERLAIN. 
_.  Burns?s concludes that in Proserpinaca palustris L. the water-environment 
R . is not the cause of the division of the leaf. He considers that the plant has two 
k, R. H., On the growth of giant bamboos, with special reference to the 
ard 
4. 
24 Davis, B. M., Studies on the plant cell. Amer. Naturalist 38:431-469. jigs. 
- 1904. 
25 Burns, G. P., a ea ie in Proserpinaca palustris L. Ann. Botany 18: 
579-605. pl. 38. 
~ 
